Brake shoe key



Patented Aug. 11, 1936 UN' lT E-D sTAT ES PATENT o Fries ZBRAKE SHOE -KEY Frederic Schaefer, 'Pittsburgh, Pa.

Application*November 9, '1935, ':Serial No. 49,069

'8 Claims,

This invention relates to keys for connecting railway 'brake shoes 'to brake heads, and has among its objects the provision of a. brake key 'which may be quickly and positively locked in position, which can 'notaccidentally 'become unlocked in service, which'is easily unlocked when 'desired, and which'i's simple, durable and inex- *pensive in construction.

The 'preferred embodiment of the invention -is 1 'illustrated in the accompanying drawing-inwhich Fig. 1 is a'side view of -the key inserted through the cooperating lugs of a* brake head and shoe'but not locked therein; Fig. 2 is a view similar to Fig. 1 showing the key locked in place; Fig. 3 is a face 15 view of the key looking at it from the left as seen in Fig. 2; and Fig. 4 is a view of the opposite face of the key.

Referring to Fig. 1 of the drawing, a brake shoe l having a central lug 2 is shown associated with a brake head 3 provided with a pair of lugs 4 straddling lug 2. All of these parts are of standard construction. The brake shoe is connected to the brake head by a key extending through the cooperating lugs and comprising a 25 pair of arms 6 and 'I, preferably resilient, slidably connected together at their opposite ends to permit arm 'I to be moved longitudinally of arm 6. Thus, the lower end of arm 6 is shown as being ofiset toward the brake shoe with the Connecting 30 portion of the arm provided with a. slot 8 in which a tongue 9 formed on the lower end of arm 'I is slidably disposed. The upper end portion of arm 6 is bent over the top of the brake shoe to limit downward movement of the key relative 35 thereto, and a slot '2 is formed in portion Il by cutting a tongue '3 in the arm and bending it back as shown. A tongue '4 formed on the upper end of arm 'I is slidably disposed in slot '2, and to provide for moving arm 'I longitudinally rela- 40 tive to arm 6 the upper end of this tongue is coiled around a pin '6 traversing a recess in a latch l" having the general form of a bell crank lever. When the long arm of the latch extends upwardly, as shown in Fig. 1, arm 'I is in its lowest 45 position relative to arm 6, but when the long arm of the latch is swung toward the brake head arm is raised thereby relative to the opposite arm as shown in Figs. 2, 3, and 4. In this position the long arm of the latch rests on tongue '3.

50 It is a feature of this invention that the key is locked in position when arm 'I is raised relative to arm 6 in the manner just described. Accordingly, upward movement of arm 'I causes a. dent or boss '8 on the inner face of that arm to ride 55 up the inclined upper wall of a depression '9 formed in 'the adjoining arm, and to thereby I spread the two arms apart and into firm engagewitha-detent 2' projecting from its outer face below upper lug 4 past which the detent can not move. To positively maintain the arms spread 'apart below detent 2I, arm 6 also is preferably provided with a detent 22 that engages the inner 10 When latch '1 is swung upwardly and toward the brake shoeto lower arm 'I, boss '8 is received in depression'l'S and detent/ 22 is received in the depression formed by detent 2', whereby the arms are permitted to collapse into engagement with each other throughout the major portion of their length as shown in Fig. 1. This leaves sufilcient clearance between the key and lugs to allow detent 2' to pass upper lug 4 so that the key can be withdrawn from the lugs to permit the brake shoe to be removed from the head. The upper portion of tongue '3, besides forming a support for the latch, is also used in driving the key into and out of position.

A brake key constituted in accordance with this invention is simple and durable in construction, but can be positively locked in position by merely swinging the latch downwardly toward the brake head. Furthermore, although the key can not become accidentally unlocked in service and permit the brake shoe to drop, it can be readily unlocked when desired by merely raising the latch.

,According to the provisions of the patent statutes, I have explained the principle and construction of my invention and have illustrated and described what I now consider to represent its best embodiment. However, I desire to have it understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically illustrated and described.

I claim:

1. A key for connecting a brake shoe to a brake head, comprising a pair of adjoining overlapping arms connected to each other for relative longitudinal movement, means for spreading said arms apart and into shoe-1ocking position when subjected to said movement, and means for effecting said longitudinal movement to: spread said arms.

2. A key for connecting a brake shoe to a brake head, comprising a pair of adjoining overlapping arms slidably connected to each other for relative longitudinal movement, means integral With said arms for spreading said arms apart and into shoe-looking position When subjected to said movement, and means for effecting said longitudinal movement to spread said arms.

3. A key for Connecting a brake shoe to a brake head having cooperating lugs, comprising a pair of adjoining overlapping arms slidably connected to each other for relative longitudinal movement and provided with a lug-engaging detent and means for spreading said arms apart and into shoe-looking position when subjected to said movement, and means for efiecting said longitudinal movement to spread said arms.

4. A key for connecting a brake shoe to a brake head, comprising a pair of adjoining overlapping arms slidably connected to each other at one end for relative longitudinal movement, means for spreading said arms apart and into shoe-looking position when subjected to said movement, and means for efiecting said longitudinal movement to spread said arms and lock them there.

5. A key for Connecting a brake shoe to a brake head, comprising a pair of adjoining overlapping arms slidably connected to each other at one end for relative longitudinal movement, means for spreading said arms apart and into shoe-looking position when subjected to said movement in one direction, and means for affecting said longitudina] movement in both directions and for looking said arms in shoe-locking position.

6. A key for Connecting a brake shoe to a brake head having cooperating lugs, comprising a pair of adjoining overlapping arms slidably connected to each other at one end for relative longitud'nal movement and provided with a lug-engaging detent, said arms also being provided with interengaging detents for spreading said arms apart and into shoe-looking position when moved relative to each other, and means for efiecting said movement to spread the arms and retain them in that position.

7. A key for Connecting a brake shoe to a brake head having cooperating lugs, comprising a pair of adjoining overlapping arms extending through said lugs, one of said arms being provided at one end with a slot and the other arm being provided with a tongue slidably disposed in the slot, one of said arms having a lug-engaging detent for looking the key in the lugs when said arms are spread apart, said arms being provided with means for spreading the arms apart when they are moved longitudinally relative to each other, and means for effecting said longitudinal movement and for looking the arms in spread-apart position.

8. A key for Connecting a brake shoe to a brake head, comprising a pair of adjoining overlapping arms provided at their opposite ends with cooperating tongues and slots permitting one arm to be moved longitudinally of the other, and a latch pivotally mounted on the upper end of said movable arm for efiecting said movement and retaining it in selected positions, and means for spreading said arms apart and into shoe-looking position when said movable arm is moved in a predeterm'ned direction.

FREDERIC SCHAEFER. 

